All runs are on the same DynoJet where I have over 80pulls on my car and is is very consistant

The test consisted of 6 pulls with mobile 1 5-30 (had 200 miles on it) all of which were at 507-508rwp there was no variation greater than the 1 hp

I then switched to the German castrol 0-30 (0 miles) and all 7 pulls were 503-504 rwp no change in tuning or anything else.

To make sure that the Fresh oil was not the cause of the HP loss I then put New mobile 1 5-30 in and Made 2 pulls at 507 rwp.

The dynographs were not worth printing as they are so close that they overlap eachother. I know how these tests go without proper proof(dynocharts) so all I have to say to that is that I am not posting this for debate or for the credibility of my test to be questioned. I did this test for my own knowledge and to help me decide which oil I would run, once I found what I did I decided to share my findings and let you take it as you may. I was hoping for the thinner German to make more power and was dissapointed, but that is why I did this test.

Actually, the "more protection" is from the GC. It has a viscosity of 11.7 vs. the Mobil-1 viscosity of 10 Cst at 100* C even though they are both 30W oils. This may be the reason for losing a couple of hp.

Good data thanks for the test. I am with vettennuts. GC is thicker. So more hp loss. It has been said many times Mobil-1 is thin. U showed this very well. I will stick with GC for more protection. If u want a few more ponys go with Mabil-1.

Actually, the "more protection" is from the GC. It has a viscosity of 11.7 vs. the Mobil-1 viscosity of 10 Cst at 100* C even though they are both 30W oils. This may be the reason for losing a couple of hp.

Dyno numbers are all fine and dandy, but I'd be more interested in the oil analysis results to see which oil produces more wear. I'd place a healthy wager that the Mobil 1 5w30 produces more wear on the engine...

wow,5-30,a little thin for me. i run kendall 20-50 for protection,a few more hp isn't worth it to me.

I would never run 20W-50 in a modern, close tolerance motor. That stuff like molasses, I don't even want to think about the kind of wear that you're putting on your motor at startup, especially when its cool/cold.

My dad switched to 15W-40 in his 89 Chevy 350 truck, and the motor blew one day while he was backing a trailer up the driveway. It was fine all the other times he towed, when it was running regular 10W-30. I cant help but think that had something to do with it.

If you look in the owners manual of your car, 20W-50 is even a consideration. I run Mobil 1 5W-30, which is reccommended, and I've been very happy with it. Full synthetic, like Mobil 1 or RP, offers much more protection than conventional oil, even though it may be much thinner. It clings to surfaces better, reduces friction between parts, keeps the inside of the motor cleaner, doesn't break down under high temps like regular oil, and also lasts much longer than conventional.

I would never run 20W-50 in a modern, close tolerance motor. That stuff like molasses, I don't even want to think about the kind of wear that you're putting on your motor at startup, especially when its cool/cold.

My dad switched to 15W-40 in his 89 Chevy 350 truck, and the motor blew one day while he was backing a trailer up the driveway. It was fine all the other times he towed, when it was running regular 10W-30. I cant help but think that had something to do with it.

If you look in the owners manual of your car, 20W-50 is even a consideration. I run Mobil 1 5W-30, which is reccommended, and I've been very happy with it.

While anecdotal evidence like that is nice, I don't think running 15w40 instead of 10w30 would have had much to do with an engine blowing up. If you'll do some looking around, you'll see that Mobil 1 5w30 is a very thin 30wt oil at operating temps. There are oil analysis reports floating around that also show that Mobil 1 5w30 doesn't do well in LS1 engines in terms of wear. These engines tend to show less wear when running a thicker oil (heavier 30wt or 40wt).

. . . There are oil analysis reports floating around that also show that Mobil 1 5w30 doesn't do well in LS1 engines in terms of wear. These engines tend to show less wear when running a thicker oil (heavier 30wt or 40wt).

I've seen a few of those posts and paid them no mind.

I've been running an MS3 or MS4 on my extreme H/C/Complete bolt-ons set-up for ~50,000 miles on a stock bottom-end LS1; I only installed the rod-bolts a few months ago.

I drive "quite spiritedly" everywhere I go at all times

EDIT: forgot to mention I've run Mobil 1 5W-30 since the Firehawk had ~500 miles on the odometer

That doesn't mean it's not wearing more by running Mobil 1. It just means it hasn't worn to the point of failure thus far. GC protects better by a long shot which has been proven time over. No one here is saying M1 is crap, it's just not as good as GC, point blank.

That doesn't mean it's not wearing more by running Mobil 1. It just means it hasn't worn to the point of failure thus far. GC protects better by a long shot which has been proven time over. No one here is saying M1 is crap, it's just not as good as GC, point blank.

Where is the evidence?? If Royal Purple is THAT much better than Mobil 1, then why do manufacturers of high performance engines use M1 as factory fill instead of RP??

I honestly can't see how it can be any better in terms of wear. It may last longer due to more additives and such, but I find it hrd to believe that there would be a measureable difference in wear of a motor that runs RP and one that runs M1.